PESA RCP-48X, Руководство пользователя

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Section 4
FUNCTIONAL
4
DESCRIPTION
page 4.5
RCP–48X
Functional
Signal Start End
SEL0 0000h 07FFh
SEL1 0800h 0FFFh
SEL2 1000h 17FFh
SEL3 1800h 1FFFh
SEL4 2000h 27FFh
SEL5 2800h 2FFFh
SEL6 3000h 37FFh
SEL7 3800h 3FFFh
Table 4–1 Decoder Addressing
Miscellaneous
The CPU board provides some special function signals for use by external
boards. R3/R4 provide a contrast adjustment for LCD displays. The CON-
TRAST signal is available for use by external boards on J2 pin 13. Like-
wise, R5 provides a brightness control signal for use by external boards. It
is available on J2 pin 14. J2 pin 9 is a signal named DSP_RS. This signal
is a register select signal for external LCD displays. The processor interrupt
request line IRQ is not currently used, but is available for use by external
board on J2 pin 12. The CPU board accepts input from a rotary encoder in
the form of two signals named KNOB0 and KNOB1. The CPU software
expects quadrature-encoded signals to indicate direction of travel from the
rotary encoder. These two signals are present on J2 pins 5 and 6.
4.3 Switchcard
RCP–48X Switchcard
The switchcard for the RCP–48X panel contains circuitry to provide a
switchcard ID for the CPU board, scan a keyboard, light the keyboard
LEDs, and interface to an optional I/O board. The following is a description
of each of these circuits.
Switchcard ID
The RCP–48X switchcard provides a six-bit ID available to be read by the
CPU board. This ID is available on J2, pins 23-28. The least significant bit
(ID0) is provided by the optional I/O board on J3 pin 5. If the I/O board is
not installed, then ID0 is pulled high by a pullup resistor on the CPU
board. If the I/O board is installed, then the ID0 pin is grounded. The CPU
may use this bit to detect the presence or absence of the I/O board. The
CPU Board Continued: